Fire-Resistant Hydraulic Fluids

ABSTRACT

A synthetic and semi-synthetic fire-resistant hydraulic fluid compositions are disclosed. According to one preferred embodiment, the composition may include water, a hydrophilic co-solvent, an oil, a lubricant, a neutralizing agent, a non-ionic surfactant, an anionic surfactant. Optionally, the compositions may further include a corrosion inhibitor, an anti-foaming agent and a biocide.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to Canadian Patent Application No. 3,124,140, filed Jul. 9, 2021. The entire specification and figures of the above-referenced application are hereby incorporated, in their entirety by reference.

FIELD OF THE INVENTION

The present invention is directed to a fire-resistant hydraulic fluid (FRHF), more specifically to a semi-synthetic and a fully synthetic fire-resistant hydraulic fluids.

BACKGROUND OF THE INVENTION

Hydraulic fluids are critical to industrial machinery and serves many purposes in industrial applications. Technological advances in industrial equipment result in changing needs from the hydraulic fluids used in these equipments. Consequently, there is a need to ensure that hydraulic fluids can meet the needs of operators while meeting regulatory requirements as well as equipment manufacturers' specifications. The majority of hydraulic components and systems are designed to use oil-based hydraulic fluids.

Many industries utilize fire-resistant hydraulic fluids including power transmission plants; hydraulics systems operating in areas which are prone to risks of potential fires, including but not limited to steel mills, metal die casting machinery; welding machinery; foundries as well as hydraulic roof support in coal mines.

While there are many different components and additives in hydraulic fluids, there are four basic classes: straight oils; soluble oils (emulsifiable oils); semi-synthetic fluids; and synthetic fluids.

Petroleum-based oils (also referred to as straight oils are also called “cutting” or “neat” oils) are made up of mineral (petroleum), animal, marine, vegetable, or synthetic oils. Today, the mineral oils are “severely solvent refined” or “severely hydrotreated”. These terms refer to refining processes that help reduce the amount of polynuclear aromatic hydrocarbons (PAHs). Straight oils are not diluted with water but other additives may be present.

Soluble oils (also referred to as emulsifiable oils) represent a category which contains 30 to 85 percent severely refined petroleum oils, as well as emulsifiers to disperse the oil in water.

Semi-synthetic fluids represent a category which contains 5 to 30 percent severely refined petroleum oils, 30 to 50 percent water, and a number of additives.

Synthetic fluids represent a category which does not contain petroleum oils. Instead, they use detergent-like components and other additives to help “wet” the workpiece. Synthetic fluids initially contained compounds known as phosphate esters. While providing excellent fire resistance their adoption has been in decline primarily because of environmental concerns, prohibitive costs, and compatibility concerns. Another type of synthetic fluid includes synthetic hydrocarbons, such as polyol esters. Polyol ester-based hydraulic fluids are combined with a number of additives such as anti-wear agents, corrosion inhibitors, and viscosity modifiers. These fluids provide good fire resistance and are the most recent category of FRHFs and have gained widespread and growing use. However, concerns over costs plague these fluids.

Although each class will vary greatly in composition, each may contain additives such as: sulfurized or chlorinated compounds; corrosion inhibitors (e.g., calcium sulfonate, sodium sulfonates, fatty acid soaps, amines, boric acid); extreme pressure additives (e.g., sulfurized fatty materials, chlorinated paraffins, phosphorus derivatives); anti-mist agents (e.g., polyisobutylene polymer); anti-weld agents; emulsifiers (e.g., triethanolamine, sodium petroleum sulphonates, salts of fatty acids and nonionic surfactants); alkanolamines; biocides (e.g., triazine compounds, oxazolidine compounds); preservatives; stabilizers; dispersants; defoamers; colourants; dyes; odourants; and fragrances.

Petroleum-based oil used in mobile industrial equipment has many excellent characteristics and is highly desirable as a hydraulic fluid. It is non-corrosive, compatible with a wide variety of seals, has good lubricating properties, is readily available, and is relatively cheap. The main drawback of such fluids is the low flashpoint of between 300° F. and 600° F. (148° C. to 316° C.).

Since hydraulic fluids are exposed to high heat and high-pressure conditions, and are released from leaking hoses and seals as a mist or spray, the danger is very real. During operation, damage to hydraulic equipment is usually due to fire, as a result of damaged hydraulic hoses, some can be tears, breaks and some may just be small pinhole leaks. A hydraulic fire resulting from a leak of hydraulic fluid can propagate very quickly and burn so hot that a fire extinguisher may not be sufficient to extinguish it.

Preventing or minimizing fire damage allows operators to avoid extended equipment downtime, equipment damage, and clean-up costs. Replacing the original equipment manufacturer's hydraulic fluid with fire-resistant fluids all the while maintaining the original fluid's performance characteristics is highly desirable and can lead to circumventing many of the above-mentioned drawbacks of non-fire-resistant fluids.

Less hazardous and more fire-resistant hydraulic fluids are water glycols, oil-in-water emulsions, and synthetic fluids. Fire-resistant hydraulic fluids have been developed to replace petroleum-based fluids in applications where there is a potential ignition source. A variety of hydraulic fluid formulations are available, so selecting the appropriate fluid for a given purpose should be based on a review of the characteristics of each fluid.

While fire-resistant fluids have a lower fire hazard than petroleum oil, all will ignite under extreme conditions. Although fire-resistant fluids are not fireproof, they do substantially reduce the potential hazard associated with petroleum-based fluids.

While the term “fire-resistant” may be somewhat ambiguous, the industry has developed various testing requirements in order to standardize the fluids. While there is no single property or test which will allow one to rate a composition (fluid) as being fire resistant, various tests have been developed to simulate incidents. These tests are designed to mimic worst-case scenarios in typical applications where fluid power is used near a potential fire hazard. Fluids which successfully pass these tests are incorporated into an Approval Guide or List of Qualified Fluids.

Generally, the expression fire-resistant relating to such fluids implies that, according to a first test, they significantly reduce the potential hazard associated with oil-based products. In the Factory Mutual Research Corporation (FMRC) tests, the fluid is conditioned to 140° F., pressurized to 1000 psi in a steel cylinder, and discharged through an oil burner-type nozzle. The spray generated is intended to simulate a high-pressure hydraulic system leak. A gas flame is passed through (not retained in) the spray envelope at two distances downstream of the nozzle. There may be local burning at the point of flame entry, and the pass criteria dictate that any flame must self-extinguish when the ignition source is removed; no flame may propagate back to the nozzle. This process is repeated 20 times, and the burn duration is timed. Any burn duration over 5 sec is considered a fail.

A second type of test used to rate fire-resistant hydraulic fluids uses a spray directed at an inclined metal channel heated to 1300° F. In this test, the spray is continuous for 60 sec. The criteria include: that the spray in contact with the channel may not burn, or if spray ignition takes place, fluid rolling off the channel cannot continue to burn, and the flame cannot follow the spray if directed away from the channel. In the event that a composition passes those two conditions, it will be approved. Passing those tests is very difficult and as these are quite demanding conditions to meet.

Fire-resistant hydraulic fluid classification (according to ISO 6743/4), include:

-   -   HETG=Hydraulic Environmental Triglycerides (relate to         biodegradable (vegetable oil-based) hydraulic fluids which use         triglyceride esters as base fluid);     -   HEES=Hydraulic Environmental Ester oil Synthetic (relate to         biodegradable hydraulic fluids which use synthetic esters as         base fluid);     -   HEPG=Hydraulic Environmental Polyalkylene Glycols (relate to         biodegradable hydraulic fluid which uses polyalkylene glycols         (PAGS) as base fluid);     -   HEPR=Hydraulic Environmental PAO and Related products (relate to         biodegradable hydraulic fluids which use polyalphaolefins and         related hydrocarbons as base fluid.)

Water glycol fluids exhibit very good low-temperature properties and good viscosity-temperature behavior, with normal operating temperatures of 120° F.-130° F. (49° C. to 54° C.). Operating temperatures above 150° F. (65.5° C.) can cause water evaporation from the solution, which increases the viscosity and decreases the fire resistance of the fluid. To ensure proper water content, and corrosion protection, the fluid must be monitored regularly in close tolerance systems. Seals, hoses, and packing designed for use with petroleum fluids can be easily adapted for use with water glycol.

Water-in-oil (invert) emulsions are made up of finely divided particles of water which are dispersed throughout a continuous outer phase of oil. This type of fluid has poor low-temperature properties because the dispersed water phase can freeze, and in some products irreversibly destroy the emulsion stability (although some products can contain antifreeze additives). Normal operating temperature ranges from 120° F.-130° F. (49° C.-54° C.). Operating temperatures above 150° F. (65.5° C.) can cause water evaporation from the solution, which increases the viscosity and decreases the fire resistance of the fluid. These fluids are compatible with most seals and gaskets, and with hoses designed for use with petroleum fluids. An invert emulsion typically contains approximately 40% water dispersed in oil. The outer phase, oil, represents the wetting surface; while the water is present as fire-retardant component.

Synthetic fluids (made with polyol ester have an operational temperature limit of 175° F., but some can be used at temperatures above 200° F. They are easily adaptable to hydraulic systems designed originally for oil-based fluid, especially since pump derating is not required, and lubrication is comparable to oil-based fluid. Temperature/viscosity behavior is not compromised by use. Synthetic fluids are typically compatible with seals, gaskets, and hoses made from nitrile and fluorocarbon, but not butyl or ethylene propylene rubber (EPR).

Some of the most common concerns raised by current commercially used compositions where 70% of the products on the market are semi-synthetic with 15-20 wt % mineral oil and 25 wt % surfactants, include: fire resistance; thermal stability; and/or plugging of the filters by bacteria.

Water-glycol fluids consist of a solution of water, ethylene or diethylene glycol, a thickener, and an additive package. The additive system contains attributes such as wear protection corrosion resistance, metal passivation, oxidation resistance, antimicrobial properties, and dyes for fluid identification.

The development of water-glycol hydraulic fluids has been driven by a multitude of changes impacting various industries. A prime example is environmental concerns that have driven industries to look for fluids that are less harmful to the environment, more easily cleaned up, and also biodegradable.

Fire safety is another critical area. Water-glycol fluids are fire-resistant, and as industries move to higher operating pressures, the risk of fire increases from ruptured lines. In addition, concerns around equipment life spans, service intervals, and targets focusing on reducing the total cost of ownership are prompting industries to embrace the latest technologies around water-glycol fluids. They are often given strong consideration when facilities are looking to upgrade their hydraulic fluids.

Water-based hydraulic systems have been traditionally used in underground mining applications and steel mills and foundries, where the obvious advantage offered was fire resistance.

U.S. Pat. No. 4,010,105 teaches a stable, fire-resistant hydraulic fluid of the oil-in-water emulsion type having the property of relatively uniform viscosity over a broad range of water contents in which the non-polar (oil) and polar (water) components are coupled by means of a combination of an emulsifier, and a mixture of a relatively high molecular weight polyglycol or alkyl-substituted polyglycol and a relatively low molecular weight glycol.

US patent application no. 2009/0242858A1 discloses a method for using a water-based fluid composition to lubricate metal-metal surfaces in contact with each other in a non-hydraulic system, wherein at least one of the metal surfaces is moving. It also discloses a water-based fluid composition for use as a lubricant in the described method.

As new water-glycol compositions were developed, additive packages such as anti-wear and anti-corrosion capabilities were incorporated into the fluid. Biodegradable compositions were sought after to create an environmentally acceptable hydraulic fluid. Water-glycol hydraulic fluids offer many advantages in their industrial application over other hydraulic fluids, including: lower clean-up cost; safety (reduced fire hazard related to the storage, handling, and use thereof); rust and corrosion protection; consistent service life.

Excellent fire resistance coupled with reasonable cost and performance makes water-glycol fluids a good choice for many industrial applications. However, operators cannot simply drain a mineral oil-based hydraulic system and replace the fluid with a water-glycol formulation. Water-glycol formulations are not compatible with mineral oil formulations and mixing the two might result in deposits that may be difficult to remove. These limitations slow down the adoption of fire-resistant fluids and consequently the replacement of original petroleum-based hydraulic fluids.

Water-based hydraulic fluids will continue to gain in popularity in order to overcome more and more stringent environmental regulations given that some jurisdictions already classify “hydraulic oil” as a hazardous material.

In light of the state of the art, there is an evident need for novel fire-resistant hydraulic fluid compositions which overcome at least some of the drawbacks of known composition. It is desirable to address some environmental issues as these fluids are typically used and disposed of in the environment without any pre-treatment prior to disposal.

SUMMARY OF THE INVENTION

The inventors have developed two novel hydraulic fluid compositions in order to overcome some of the shortcomings of commercially available fire-resistant hydraulic fluid compositions. In that respect, the compositions related to Fire Resistant Hydraulic Fluid (FRHF); HFA-E (O/W microemulsion with pale oil), and HFA-S (fully synthetic with no oil).

According to a preferred embodiment of the present invention, both compositions are concentrates which are intended to be diluted onsite down to 2% v/v in water available onsite.

According to a preferred embodiment of the present invention, the compositions are intended for use on long roof support in the mining industry. These types of compositions are highly regulated products which, up until the summer of 2021, needed to pass the Original Equipment Manufacturer (OEM) testing. The two main OEMs are Joy and Caterpillar. The compositions are then eligible for registration with MHSA (Mining Health & Safety Association).

According to an aspect of the present invention, there is provided a semi-synthetic fire-resistant hydraulic fluid composition, said composition comprising:

-   -   water in an amount ranging from 25-65 wt %;     -   a hydrophilic co-solvent present in an amount ranging from 5 to         20 wt %;     -   an oil component present in an amount ranging from 1-30 wt %;     -   a lubricant present in an amount ranging from 1 to 10 wt %;     -   optionally, a vapor corrosion inhibitor (VCI) present in an         amount ranging from 1 to 10 wt %;     -   a neutralizing agent (which neutralizes the tall oil fatty acid)         present in an amount ranging from 1 to 10 wt %;     -   a nonionic surfactant present in an amount ranging from 5 to 25         wt %;     -   an anionic surfactant present in an amount ranging from 5 to 25         wt %;     -   optionally, a corrosion inhibitor present in an amount ranging         from 0.5 wt % to 5 wt %;     -   optionally, an anti-foaming agent present in an amount ranging         from 0.5 wt % to 5 wt %; and     -   optionally, a biocide present in an amount ranging from 0.5 wt %         to 5 wt %.

Preferably, the composition further comprises a chelating agent present in an amount ranging from 2 to 15 wt %.

According to a preferred embodiment of the present invention, the oil component is pale oil. Preferably, the oil component is present in an amount ranging from 5 wt % to 20 wt %.

According to a preferred embodiment of the present invention, the lubricant is a tall oil fatty acid. Preferably, lubricant is present in an amount ranging from 2-5 wt %.

According to a preferred embodiment of the present invention, the neutralizing agent is selected from the group consisting of: primary amine, tertiary amines.

According to a preferred embodiment of the present invention, the nonionic surfactant is a linear alcohol ethoxylate with C9 to C15, ethylene oxide 1 to 10. Preferably, the nonionic surfactant and the anionic surfactant are present in a weight ratio ranging from 1:3 to 3:1. Preferably, the nonionic surfactant is selected from the group consisting of: Novel® 23E3.

According to a preferred embodiment of the present invention, the anionic surfactant is selected from the group consisting of: sulfonate surfactant; disulfonate surfactant; and DDBSA and combinations thereof. Preferably, the anionic surfactant is selected from the group consisting of: Dowfax® 10CL.

According to a preferred embodiment of the present invention, the VCI and the neutralizing agent are the same compound. Preferably, the VCI is selected from the group consisting of: monoethanolamine; triethanolamine; and the like.

According to a preferred embodiment of the present invention, the composition comprising an emulsion having a particle diameter size of less than 10 nm (MEA).

According to another preferred embodiment of the present invention, the composition comprising an emulsion having a particle diameter size of less than 150 nm (TEA).

According to another preferred embodiment of the present invention, the neutralizing agent is selected from the group consisting of: choline chloride

According to another aspect of the present invention, there is provided a synthetic fire-resistant hydraulic fluid composition, said composition comprising:

-   -   water in an amount ranging from 25-65 wt %;     -   a hydrophilic co-solvent present in an amount ranging from 5 to         20 wt %;     -   a polyalkylene glycol compound present in an amount ranging from         1 to 30 wt %;     -   a lubricant present in an amount ranging from 1 to 10 wt %;     -   optionally, a vapor corrosion inhibitor (VCI) present in an         amount ranging from 1 to 10 wt %;     -   a neutralizing agent present in an amount ranging from 1 to 10         wt %;     -   optionally, a corrosion inhibitor present in an amount ranging         from 0.5 wt % to 5 wt %;     -   optionally, an anti-foaming agent present in an amount ranging         from 0.5 wt % to 5 wt %; and     -   optionally, a biocide present in an amount ranging from 0.5 wt %         to 5 wt %.

According to another preferred embodiment of the present invention, the composition further comprises a chelating agent present in an amount ranging from 2 to 15 wt %.

According to another preferred embodiment of the present invention, the polyalkylene glycol compound is selected for the group consisting of: UCON® 75-H-90,000 and while UCON® 50-HB-100.

According to another preferred embodiment of the present invention, the polyalkylene glycol component is present in an amount ranging from 5 wt % to 20 wt %.

According to another preferred embodiment of the present invention, the lubricant is a tall oil fatty acid. Preferably, the lubricant is present in an amount ranging from 1-5 wt %.

According to another preferred embodiment of the present invention, the neutralizing agent is selected from the group consisting of: primary amine, tertiary amines.

According to another preferred embodiment of the present invention, the VCI and the neutralizing agent are the same compound. Preferably, the VCI is selected from the group consisting of: monoethanolamine; triethanolamine; and the like and combinations thereof.

According to another preferred embodiment of the present invention, the neutralizing agent is selected from the group consisting of: choline chloride.

According to another aspect of the present invention, there is provided a use of a semi-synthetic hydraulic fluid composition as described previously as a hydraulic fluid in mine roof supports.

According to yet another aspect of the present invention, there is provided a use of a synthetic hydraulic fluid composition as described previously as a hydraulic fluid in mine roof supports.

According to yet another aspect of the present invention, there is provided a semi-synthetic fire-resistant hydraulic fluid composition consisting of:

-   -   water in an amount ranging from 25-65 wt %;     -   a hydrophilic co-solvent present in an amount ranging from 5 to         20 wt %;     -   an oil component present in an amount ranging from 1-30 wt %;     -   a lubricant present in an amount ranging from 1 to 10 wt %;     -   a vapor corrosion inhibitor (VCI) present in an amount ranging         from 1 to 10 wt %;     -   a neutralizing agent (which neutralizes the tall oil fatty acid)         present in an amount ranging from 1 to 10 wt %;     -   a nonionic surfactant present in an amount ranging from 5 to 25         wt %;     -   an anionic surfactant present in an amount ranging from 5 to 25         wt %;     -   a corrosion inhibitor present in an amount ranging from 0.5 wt %         to 5 wt %;     -   an anti-foaming agent present in an amount ranging from 0.5 wt %         to 5 wt %; and     -   a biocide present in an amount ranging from 0.5 wt % to 5 wt %.

According to another aspect of the present invention, there is provided a synthetic fire-resistant hydraulic fluid composition, said composition consisting of:

-   -   water in an amount ranging from 25-65 wt %;     -   a hydrophilic co-solvent present in an amount ranging from 5 to         20 wt %;     -   a polyalkylene glycol compound present in an amount ranging from         1 to 30 wt %;     -   a lubricant present in an amount ranging from 1 to 10 wt %;     -   optionally, a vapor corrosion inhibitor (VCI) present in an         amount ranging from 1 to 10 wt %;     -   a neutralizing agent present in an amount ranging from 1 to 10         wt %;     -   optionally, a corrosion inhibitor present in an amount ranging         from 0.5 wt % to 5 wt %;     -   optionally, an anti-foaming agent present in an amount ranging         from 0.5 wt % to 5 wt %; and     -   optionally, a biocide present in an amount ranging from 0.5 wt %         to 5 wt %.

BRIEF DESCRIPTION OF THE FIGURES

Features and advantages of embodiments of the present application will become apparent from the following detailed description and the appended figures, in which:

FIG. 1 is a particle size distribution graph of a preferred composition (HFA-E) according to the present invention at 25° C.; and

FIG. 2 is a graph of the viscosity of various tested compositions according to the present invention.

DESCRIPTION OF THE INVENTION

In the development of novel fire-resistant compositions, some key considerations had to be taken into account. These considerations included: the resulting composition will be diluted using any one of: city water, river water, and in rare cases there might be a water treatment system onsite. The quality of the water is very poor. Foaming in the tanks is another issue. The product is injected using a piston plunger pump of 5000 psi down a 1000 ft then through the longwall shield. The temperatures to which the compositions will be exposed are around 105-110° F. (40-43° C.) and are at a maximum 140° F. (60° C.). The lifetime of the product in the system is around 1 hour before it is discarded and leaks onto the ground. The product should not cause any dermal issues. The presence of biocides, bactericides, fungicides is desirable. The right package should be selected carefully. The compositions will be exposed to materials such as: mostly chromium, bronze, aluminum, cast iron. Exposure to stainless steel is very rare. Original equipment manufacturers (OEM) have specific requirements. The compositions should be compatible with aluminum. Corrosion inhibitors included in the compositions should also have effectiveness in protecting against corrosion on zinc and cast iron. In the case of synthetic compositions, PEG (polyethylene glycol) is more efficient than caprylic acid. Amine load controls the pH (pH<11). Lowering the mineral oil content in the fluid reduces the food source for bacteria and fungus, increases biodegradability, and reduces the ability for mineral oil to form deposits in longwall machinery. Other considerations of importance are that operators cannot simply drain a mineral oil-based hydraulic system and replace the fluid with a water-glycol formulation. Water-glycol formulations are not compatible with mineral oil formulations and mixing the two might result in deposits that may be difficult to remove.

Some of the most common concerns raised by current commercially used compositions where 70% of the products on the market are semi-synthetic with 15-20 wt % mineral oil and 25 wt % surfactants include: fire resistance; thermal stability; and/or plugging of the filters by bacteria.

The following is a list of the materials (specific compounds or classes of compounds) which were incorporated into the compositions at one point or another and are generally representative of several compounds or an entire class of compounds: chelating agents (such as Na₄EDTA); Butyl Carbitol; Monoethanolamine (MEA); Triethanolamine (TEA); Choline Chloride; tall oil fatty acids (TOFA-1); Dowfax® C10L; Novel® 23E3; corrosion inhibitor (CIX-2); Emuldac® 251PE; biocides; Mineral oil; Pale Oil 40; UCON 75-H-90,000°; and UCON 50-HB-100®. CIX-2 is a proprietary blend comprising beta-Alanine, N-(2-carboxyethyl)-N-dodecyl-, monosodium salt (e.g. Basocorr 2005), and citral prepared in Diethylene glycol mono butyl ether (e.g. butyl carbitol). It provides corrosion protection for most metals tested including aluminum. Tolyltriazol, the most common corrosion inhibitor (CI) used in the industry, is very toxic and is not present in the compositions according to a preferred embodiment of the present invention. It is preferable that the corrosion inhibitor be biodegradable and environmentally friendly.

Semi-Synthetic Formulations

The base composition comprising water; butyl carbitol; tall oil fatty acid; monoethanolamine; an oil component (petroleum-derived); an anionic surfactant; and a nonionic surfactant was used to study the impact of various additives. Ultimately, a composition comprising several additives to allow for multifunctionality was developed using monoethanolamine as a vapor corrosion inhibitor (VCI). Other additives were studied and incorporated into the formulation. As the anionic surfactant, Dowfax® C10L was selected because it is a disulfonate surfactant having high stability in hard water. For nonionic surfactant, it is a C₁₂-C₁₃ alcohol ethoxylate with 3 moles of EO. Novel® 23E3 is an ethoxylate is a biodegradable nonionic derived from SAFOL® 23 Alcohol and ethoxylated to an average of 3 moles of ethylene oxide.

The first step in the formulation design was directed to the optimization of the surfactant ratio of Dowfax®C10L and Novel®23E3.

According to a preferred embodiment of the present invention, The composition preparation procedure involved:

1. Mixing the ingredient sequentially while mixing using a magnetic stirrer;

2. Visually inspect the formulation;

3. Measure salt-tolerance by dilution in CaCl₂ solutions; and

4. Conduct formulation testing on the diluted formulations in the desired CaCl₂ solutions.

Table 2 shows various compositions having different ratios of the two surfactants. A low concentration of butyl carbitol was selected so the surfactant ratio would be optimized near the lower limit of the cosurfactant. The clarity and speed of mineral oil dissolution were observed as the mineral oil was added dropwise while mixing. Compositions BSS-4 and BSS-5 were very opaque and viscous after adding Novel® 23E3. However, both BSS-4 and BSS-5 became clear after adding the additional 1 mL of Butyl Carbitol. Composition BSS-1 did not dissolve any significant amount of oil. It was observed that when a formulation is reaching near the maximum oil dissolution, the speed of dissolution decreases significantly.

Samples were prepared by adding the components in the same order as in the table. All components dissolved easily in the solution, except for Novel® 23E3 Ethoxylate that depends on its concentration. For compositions BSS-1, BSS-2, and BSS-3, Novel®23E3 Ethoxylate dissolved in solution to form a low viscosity solution. For BSS-4 and BSS-5, once Novel® 23E3 Ethoxylate was added a gel was formed. Hence, compositions BSS-4+ and BSS-5+ were made by adding 1 mL of Butyl Carbitol to composition BSS-4 and composition BSS-5. This allowed for the dissolution of the Novel®23E3 Ethoxylate and formed a clear, low viscosity solution. A clear solution is an indication of a formed microemulsion, this can be confirmed by exposing the clear solution to dynamic light scattering.

An oil component (derived from petroleum) was added gradually to find the maximum oil solubility before the solution turned turbid or milky. However, for compositions such as BSS5+ that dissolved the total amount of oil added, the maximum oil solubility can be higher than the total amount of oil. The oil concentration in the Table is the maximum oil solubility where the microemulsion is a clear solution. Beyond this, a milky emulsion was formed. The difference between a milky emulsion and a clear microemulsion resides in the size of the droplets which are larger in the case of a milky emulsion. Above the maximum mineral oil concentration for a clear solution, the solution was opaque and then, separated into two clear phases.

As shown in Tables 2a and 2b, the solubilization parameter initially increases with decreasing the ratio of Dowfax®C10L/Novel®23E3 and then decreases as the concentration of butyl carbitol is kept constant.

TABLE 2a Effect of the ratio of surfactant mixture Dowfax ® C10L and Novel ® 23E3 BSS1 BSS2 BSS3 BSS4 g wt % g wt % g wt % g wt % Water 5.7 45.2 5.7 45.2 5.7 43.7 5.7 43.7 Butyl carbitol 0.2 1.8 0.2 1.8 0.2 1.7 0.2 1.7 MEA 1.2 9.4 1.2 9.4 1.2 9.1 1.2 9.1 TOFA-1 0.6 4.9 0.6 4.9 0.6 4.8 0.6 4.8 Dowfax ®C10L 3.0 23.8 2.5 19.8 2.0 15.3 1.5 11.5 Novel ®23E3 1.0 7.9 1.5 11.9 2.0 15.3 2.5 19.2 Mineral oil 0.9 6.9 0.9 6.9 1.3 10.0 1.3 10.0 Total 12.6 100.0 12.6 100.0 13.0 100.0 13.0 100.0 Surfactant C/NV C/SV C/SV T/VV Solution Without Oil Mineral oil(mL) 0.50 Y Milky Y C Y C X 1.00 X Y Milky Y C 1.50 X Y C 2.00 Y Milky 2.50 X 3.28 SP (mL/g) 0 0.125 0.375 0

TABLE 2b Effect of the ratio of Dowfax ® C10L and Novel ® 23E3 (continued) BSS5 BSS4+ BSS5+ g wt % g wt % g wt % Water 5.7 42.3 5.7 40.7 5.7 38.4 Butyl carbitol 0.2 1.7 1.2 8.4 1.2 7.9 MEA 1.2 8.8 1.2 8.5 1.2 8.0 TOFA-1 0.6 4.6 0.6 4.4 0.6 4.2 Dowfax ®C10L 1.1 8.0 1.5 10.7 1.1 7.2 Novel ®23E3 2.9 21.7 2.5 17.9 2.9 19.7 Mineral oil 1.7 12.9 1.3 9.3 2.2 14.6 Total 13.5 100.0 14.0 100.0 14.9 100.0 Surfactant T/VV C/NV C/NV Solution Without Oil Mineral oil (mL) 0.50 X Y C Y C 1.00 Y C Y C 1.50 Y C Y C 2.00 Y C Y C 2.50 Y Milky Y C 3.28 X Y C SP (mL/g) 0 0.5 0.82

Based on the information contained in Tables 2a and 2b that the best performing Dowfax®C10L/Novel 23E3 had a ratio of 1:3. Table 3 presents the effect of the concentration of Butyl Carbitol for Dowfax® C10L/Novel® 23E3 of 1:3. It was found that the optimum concentration of Butyl Carbitol is between 8 to 10%. Meanwhile, the minimum concentration of Butyl Carbitol to dissolve Novel® 23E3 in solution is greater than 3.52%. For BSS6, after adding Novel® 23E3, it was a very viscous and opaque solution. At higher concentrations of Butyl Carbitol, the solution was clear and non-viscous after the addition of the surfactant Novel®23E3. However, the solubilization parameter (SP) decreases as the concentration of Butyl Carbitol increases above the optimum concentration.

TABLE 3 Effect of the concentration of Butyl Carbitol for DOWFAX C10L/NOVEL 23E3 of 1:3 BSS6 BSS7 BSS11 BSS8 BSS9 BSS10 g wt % g wt % g wt % g wt % g wt % g wt % Water 5.7 40.2 5.7 38.3 5.7 37.5 5.7 36.3 5.7 39.3 5.7 36.7 Butyl carbitol 0.5 3.5 1.2 7.9 1.5 9.9 2.0 12.7 3.0 20.7 4.0 25.8 MEA 1.2 8.4 1.2 8.0 1.2 7.8 1.2 7.6 1.2 8.2 1.2 7.7 TOFA-1 0.6 4.4 0.6 4.2 0.6 4.1 0.6 4.0 0.6 4.3 0.6 4.0 Dowfax ®C10L 1.0 7.0 1.0 6.7 1.0 6.6 1.0 6.4 1.0 6.9 1.0 6.4 Novel ®23E3 3.0 21.1 3.0 20.2 3.0 19.8 3.0 19.1 3.0 20.7 3.0 19.3 Mineral oil 2.2 15.3 2.2 14.6 2.2 14.3 2.2 13.9 2.2 15.0 2.2 14.0 Total 14.2 100.0 14.9 100.0 15.2 100.0 15.7 100.0 14.5 100.0 15.5 100.0 Surfactant T/VV C/NV C/NV C/NV C/NV C/NV Solution Mineral oil (mL) 0.50 X Y C Y C Y C Y C/NV Y C 1.00 Y C Y C Y C Y C Y C 1.50 Y C Y C Y C Y C Y C 2.00 Y C Y C Y C Y C Y T 2.50 Y C Y C Y C Y T 3.28 Y C Y C Y T SP (mL/g) 0 0.82 0.82 0.625 0.5 0.375

Additives to the Composition

According to a preferred embodiment of the present invention, additional additives need to be included to control certain characteristics such as salt tolerance, corrosion inhibition, anti-foam, and biocides. Some of these additives may change the equilibrium of the composition and the intermolecular interaction between the surfactants.

The first additives which were incorporated included: a corrosion inhibitor; an antifoam agent and a biocide. These were added to composition BSS11. Preferably, the corrosion inhibitor comprises a monoterpene (acyclic); monocyclic terpene; and beta-lonone. Exemplary but non-limiting compounds of some of the previously listed terpene sub-classes comprise: for monoterpenes: citral (mixture of geranial and neral); citronellal; geraniol; and ocimene; for monocyclic terpenes: alpha-terpinene; carvone; p-cymene. More preferably, the terpenes are selected from the group consisting of: citral; ionone; ocimene; and cymene. Preferably, another component may comprise the corrosion inhibitor which can be an iminodipropionic acid (i.e. Basocorr® 2005). Preferably also, the corrosion inhibitor comprises a carrier liquid such as a glycol ether, or an ethoxytriglycol. Preferably, the terpene and the imidopropionic acid are mixed with the carrier liquid for at least 1 hour at 45-55° C. to ensure proper mixing.

It was determined that none of these additives seemed to have any effect on the stability of the formulation as shown in Table 4. Initially, Kathon® 886 MW Biocide was tested but was found to not be soluble in the formulation. Subsequently, Grotan® Biocide was tested and found to be compatible with the formulation.

Subsequently, a chelating agent was tested to enhance the salt tolerance of the formulation. Several concentrations of Na₄EDTA (dry granular) were added and it was determined that they had no impact on the oil solubilization.

However, when the concentration of the chelating agent is up to 3 wt % Na₄EDTA (dry granular), none of the compositions resulted in clear solutions when diluted to 2% active in 200 ppm CaCl₂ (Table 4). It was noted that when the concentration of Na₄EDTA was increased to 4 and 5 wt %, Novel® 23E3 did not dissolve in the formulation. Heating and adding more butyl carbitol did not help.

TABLE 4 Effect of the concentration of Na₄EDTA for DOWFAX C10L/NOVEL 23E3 of 1:3 BSS13 BSS14 BSS15 BSS16 BSS17 g wt % g wt % g wt % g wt % g wt % Water (pH = 7) 5.7 36.7 5.7 36.5 5.7 36.3 5.7 36.1 5.7 35.9 Na₄EDTA (dry 0.2 1.0 0.2 1.5 0.3 2.0 0.4 2.5 0.5 3.0 granular) Butyl Carbitol 1.5 9.6 1.5 9.6 1.5 9.6 1.5 9.5 1.5 9.5 MEA 1.2 7.7 1.2 7.6 1.2 7.6 1.2 7.5 1.2 7.5 TOFA-1 0.6 4.0 0.6 4.0 0.6 3.9 0.6 3.9 0.6 3.9 Dowfax ®C10L 1.0 6.4 1.0 6.4 1.0 6.4 1.0 6.3 1.0 6.3 Novel ®23E3 3.0 19.3 3.0 19.2 3.0 19.1 3.0 19.0 3.0 18.9 CIX-2 0.1 0.6 0.1 0.6 0.1 0.6 0.1 0.6 0.1 0.6 Emuldac 251PE 0.1 0.6 0.1 0.6 0.1 0.6 0.1 0.6 0.1 0.6 Biocide 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Mineral oil 2.2 14.0 2.2 13.9 2.2 13.8 2.2 13.8 2.2 13.7 Total 15.5 100.0 15.6 100.0 15.7 100.0 15.8 100.0 15.9 100.0 Surfactant Solution C/NV C/NV C/NV C/NV C/NV Mineral oil (mL) 0.50 Y C Y C Y C Y C Y C 1.00 Y C Y C Y C Y C Y C 1.50 Y C Y C Y C Y C Y C 2.00 Y C Y C Y C Y C Y C 2.50 Y C Y C Y C Y C Y C 2% Active Dilution in Clear Clear Clear Clear Clear 200 ppm CaCl2 Turbid Turbid Turbid Turbid Precipitate

The ratio of Dowfax®C10L/Novel®23E3 was increased to help in solubilizing Novel®23E3 at higher concentrations of Na₄EDTA (dry granular). To optimize the formulations, samples with different concentrations of Butyl Carbitol were prepared. Table 5 shows that the optimal concentration of Butyl Carbitol for this ratio of Dowfax® C10L/Novel®23E3 (1.5:2.5) decreased to 6.4 wt % as compared to 9.6 wt % in the case of a 1:3 ratio.

An interesting observation was made as the addition of more Dowfax®C10L, which is a disulfonate surfactant, increases the overall hydrophilicity of the formulation and hence less cosolvent (butyl carbitol) was required to reach the maximum solubilization of mineral oil.

Composition BSS24 was then retained and then diluted to 2 wt % active in CaCl₂ solutions with different concentrations (200, 400, 600, and 800 ppm). In the case of the dilution into 200 ppm CalCl₂, the composition remained transparent. Meanwhile, for higher CaCl₂ content, the dilution is translucent, however, no precipitation or separation was observed for several weeks.

When mineral oil was replaced by Pale Oil 40 (Table 6), the optimal concentration of Butyl Carbitol increased to 9.27 wt % or above. However, when composition BSS29 was diluted in CaCl₂ solutions, it was only stable in 200 ppm CaCl₂. These compositions were repeated with increasing the pH of the water to 10.5. However, the pH did not have any effect. Tolyltriazol corrosion inhibitor was then added to the formulation and it does not have any effect on the composition. The composition was also tested with up to 24% Pale Oil 40 and it yielded a clear solution.

TABLE 5 Formulation with 4% Na4EDTA (dry granular) and ratio of DOWFAX C10L/NOVEL 23E3 of 1.5:2.5 with different concentrations of Butyl Carbitol. BSS23 BSS24 BSS25 BSS26 BSS27 g wt % g wt % g wt % g wt % g wt % Water (pH = 7) 5.7 37.7 5.7 36.5 5.7 35.3 5.7 34.3 5.7 33.3 Na₄EDTA (dry 0.7 4.3 0.7 4.2 0.7 4.0 0.7 3.9 0.7 3.8 granular) Butyl Carbitol 0.5 3.3 1.0 6.4 1.5 9.3 2.0 12.0 2.5 14.6 MEA 1.2 7.9 1.2 7.6 1.2 7.4 1.2 7.2 1.2 7.0 TOFA-1 0.6 4.1 0.6 4.0 0.6 3.8 0.6 3.7 0.6 3.6 Dowfax ®C10L 1.5 9.9 1.5 9.6 1.5 9.3 1.5 9.0 1.5 8.8 Novel ®23E3 2.5 16.5 2.5 16.0 2.5 15.5 2.5 15.0 2.5 14.6 CIX-2 0.1 0.7 0.1 0.6 0.1 0.6 0.1 0.6 0.1 0.6 Emuldac 251PE 0.1 0.7 0.1 0.6 0.1 0.6 0.1 0.6 0.1 0.6 Grotan ® Biocide 0.1 0.7 0.1 0.6 0.1 0.6 0.1 0.6 0.1 0.6 Mineral oil 2.2 14.4 2.2 13.9 2.2 13.5 2.2 13.1 2.2 12.7 Total 15.1 100.0 15.6 100.0 16.1 100.0 16.6 100.0 17.1 100.0 Surfactant Solution T/V C/NV C/NV C/NV C/NV Mineral oil (mL) 0.50 X Y C Y C Y C Y C 1.00 Y C Y C Y C Y C 1.50 Y C Y C Y C Y C 2.00 Y C Y C Y C Y T 2.50 Y C Y T Y T

TABLE 6 Formulation with 4% Na₄EDTA and ratio of DOWFAX C10L/NOVEL 23E3 of 1.5:2.5 with different concentrations of Butyl Carbitol using Pale Oil 40. BSS28 BSS29 BSS30 BSS31 g wt % g wt % g wt % g wt % Water (pH = 7) 5.70 36.34 5.70 35.22 5.70 34.16 5.70 33.17 Na₄EDTA (dry 0.65 4.14 0.65 4.02 0.65 3.90 0.65 3.78 granular) Butyl Carbitol 1.00 6.37 1.50 9.27 2.00 11.99 2.50 14.55 MEA 1.19 7.59 1.19 7.36 1.19 7.14 1.19 6.93 TOFA-1 0.62 3.95 0.62 3.83 0.62 3.72 0.62 3.61 DOWFAX C10L 1.50 9.56 1.50 9.27 1.50 8.99 1.50 8.73 Novel ®23E3 2.50 15.94 2.50 15.45 2.50 14.98 2.50 14.55 CIX-2 0.10 0.64 0.10 0.62 0.10 0.60 0.10 0.58 Emuldac 251PE 0.10 0.64 0.10 0.62 0.10 0.60 0.10 0.58 Grotan ® Biocide 0.10 0.64 0.10 0.62 0.10 0.60 0.10 0.58 Pale Oil 40 2.23 14.18 2.23 13.75 2.23 13.33 2.23 12.95 Total 15.69 100.00 16.19 100.00 16.69 100.00 17.19 100.00 Surfactant Solution C/NV C/NV C/NV C/NV Pale Oil 40 (mL) 0.50 Y C Y C Y C Y C 1.00 Y C Y C Y C Y C 1.50 Y C Y C Y C Y C 2.00 Y C Y C Y C Y C 2.50 Y T Y C Y C Y C

Afterwards, the concentration of Na₄EDTA (dry granular) was increased to 5 and 6 wt % (Table 7). In the case of 5 wt % Na₄EDTA (dry granular), the surfactant solution was clear and non-viscous and then all the Pale Oil 40 was dissolved into a clear solution. However, when Na₄EDTA (dry granular) concentration was increased to 6 wt %, after adding butyl carbitol it became turbid, then after adding MEA it became a clear solution. It became very turbid again after adding Novel®23E3.

When the formulations were diluted in CaCl₂ solutions, formulation with 5 wt % Na₄EDTA formed clear solution in 200 and 400 ppm CaCl₂. However, it was turbid when diluted in 500 ppm CaCl₂.

TABLE 7 Formulation with 5 and 6 wt % Na₄EDTA and ratio of DOWFAX C10L/ Novel ®23E3 of 1.5:2.5 using Pale Oil 40 BSS44 BSS45 BSS46 wt % g wt % g wt % g Water (pH = 10.55) 34.00 5.10 33.00 4.95 32.00 4.80 Na₄EDTA (dry granular) 4.00 0.60 5.00 0.75 6.00 0.90 Butyl Carbitol 9.00 1.35 9.00 1.35 9.00 1.35 MEA 7.00 1.05 7.00 1.05 7.00 1.05 TOFA-1 3.50 0.53 3.50 0.53 3.50 0.53 DOWFAX C10L 9.00 1.35 9.00 1.35 9.00 1.35 Novel ®23E3 15.00 2.25 15.00 2.25 15.00 2.25 Tolytriazole CI 1.00 0.15 1.00 0.15 1.00 0.15 CIX-2 1.00 0.15 1.00 0.15 1.00 0.15 Emuldac 251PE 1.00 0.15 1.00 0.15 1.00 0.15 Grotan ® Biocide 1.00 0.15 1.00 0.15 1.00 0.15 Pale Oil 40 14.50 2.18 14.50 2.18 14.50 2.18 Total 100.00 15.00 100.00 15.00 100.00 15.00 Surfactant Solution C/NV C/NV T/V Pale Oil 40 (mL)  0.50 Y C Y C X  1.00 Y C Y C  1.50 Y C Y C  2.00 Y C Y C  2.50 Y C Y C 2% Dilutions in CaCl₂ (ppm) 500 Turbid Turbid 400 Turbid Clear 200 Clear Clear

To increase the loading of Na₄EDTA (dry granular) in the formulation, the ratio of Dowfax®C10L/Novel 23E3 was increased. Then compositions with different concentrations of Butyl Carbitol were prepared to find the optimal concentration of cosolvent. Table 8 shows that the optimal Butyl Carbitol concentration ranges from 3-6 wt %. When compositions BSS51 and BSS52 were diluted in 500 ppm CaCl₂ solution, they yielded clear and stable solutions for several weeks.

TABLE 8 Formulation with 6 wt % Na₄EDTA (dry granular) and ratio of DOWFAX C10L/Novel ®23E3 of 1.65:1.95 using Pale Oil 40 and different concentration of Butyl Carbitol BSS51 BSS52 BSS53 BSS54 BSS55 wt % g wt % g wt % g wt % g wt % g Water (pH = 10.55) 38.00 5.70 35.00 5.25 32.00 4.80 29.00 4.35 26.00 3.90 Na₄EDTA (dry 6.00 0.90 6.00 0.90 6.00 0.90 6.00 0.90 6.00 0.90 granular) Butyl Carbitol 3.00 0.45 6.00 0.90 9.00 1.35 12.00 1.80 15.00 2.25 MEA 7.00 1.05 7.00 1.05 7.00 1.05 7.00 1.05 7.00 1.05 TOFA-1 3.50 0.53 3.50 0.53 3.50 0.53 3.50 0.53 3.50 0.53 DOWFAX C10L 11.00 1.65 11.00 1.65 11.00 1.65 11.00 1.65 11.00 1.65 Novel ®23E3 13.00 1.95 13.00 1.95 13.00 1.95 13.00 1.95 13.00 1.95 Tolytriazole CI 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 CIX-2 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 Emuldac 251PE 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 Grotan ® Biocide 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 Pale Oil 40 14.50 2.18 14.50 2.18 14.50 2.18 14.50 2.18 14.50 2.18 Total 100.00 15.00 100.00 15.00 100.00 15.00 100.00 15.00 100.00 15.00 Surfactant C/NV C/NV T T T Solution Pale Oil 40 (mL)  2.50 Y C Y C X X X 2% Dilutions in CaCl₂ (ppm) 500 Clear Clear X X X

Optimization of Antifoam Loading

Table 9 shows the best compositions and their salt tolerance. As shown, to get to 500 ppm CaCl₂, a minimum of 6 wt % of Na₄EDTA (dry granular) is required. However, to minimize the foam lifetime of these formulations, the concentration of the antifoam needs to be increased. The antifoam is a very hydrophobic surfactant and is expected to affect the formulations at high loadings. Tables 10, 11, and 12 show variations of the best compositions in Table 9 but with increasing the concentration of the antifoam.

For composition BSS44 with 4 wt % Na₄EDTA (dry granular), with increasing the concentration of Emuldac 251PE, microemulsions were produced and the foam lifetime of the dilution in 400 ppm CaCl₂) decreases significantly.

However, for compositions BSS45 and BSS51, the surfactant solution was very turbid and hence the oil was not added. Hence, composition BSS57 was selected as the composition providing the best set of characteristics. Composition BSS57 was diluted to 40% active to get the final product (Table 13).

TABLE 9 Best formulations and their salt tolerance BSS44 BSS45 BSS51 Na₄EDTA (dry granular) (wt %) 4 5 6 Maximum CaCl₂ (ppm) 200 400 500

TABLE 10 Variations of BSS44 with increasing the Concentration of Emuldac 251PE BSS44 BSS56 BSS57 BSS58 wt % g wt % g wt % g wt % g Water (pH = 10.55) 34.00 5.10 33.00 4.95 32.00 4.80 31.00 4.65 Na₄EDTA (dry 4.00 0.60 4.00 0.60 4.00 0.60 4.00 0.60 granular) Butyl Carbitol 9.00 1.35 9.00 1.35 9.00 1.35 9.00 1.35 MEA 7.00 1.05 7.00 1.05 7.00 1.05 7.00 1.05 TOFA 3.50 0.53 3.50 0.53 3.50 0.53 3.50 0.53 Dowfax ®C10L 9.00 1.35 9.00 1.35 9.00 1.35 9.00 1.35 Novel ®23E3 15.00 2.25 15.00 2.25 15.00 2.25 15.00 2.25 Tolytriazole CI 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 CIX-2 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 Emuldac 251PE 1.00 0.15 2.00 0.30 3.00 0.45 4.00 0.60 Grotan ® Biocide 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 Pale Oil 40 14.50 2.18 14.50 2.18 14.50 2.18 14.50 2.18 Total 100.00 15.00 100.00 15.00 100.00 15.00 100.00 15.00 Surfactant Solution C/NV C/NV C/NV C/NV Pale Oil 40 (mL) 2.50 Y C Y C Y C Y C Foam life of dilution h½ > 10 min 10-15 min <10 min >10 min in 400 ppm CaCl₂

TABLE 11 Variations of BSS45 with increasing the concentration of Emuldac 251PE BSS45 BSS59 BSS60 BSS61 wt % g wt % g wt % g wt % g Water (pH = 10.55) 33.00 4.95 32.00 4.80 31.00 4.65 30.00 4.50 Na4EDTA (dry 5.00 0.75 5.00 0.75 5.00 0.75 5.00 0.75 granular) Butyl Carbitol 9.00 1.35 9.00 1.35 9.00 1.35 9.00 1.35 MEA 7.00 1.05 7.00 1.05 7.00 1.05 7.00 1.05 Tall Oil Fatty Acid 3.50 0.53 3.50 0.53 3.50 0.53 3.50 0.53 Dowfax ®C10L 9.00 1.35 9.00 1.35 9.00 1.35 9.00 1.35 Novel ®23E3 15.00 2.25 15.00 2.25 15.00 2.25 15.00 2.25 Tolytriazole CI 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 CIX-2 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 Emuldac 251PE 1.00 0.15 2.00 0.30 3.00 0.45 4.00 0.60 Grotan ® Biocide 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 Pale Oil 40 14.50 2.18 14.50 2.18 14.50 2.18 14.50 2.18 Total 100.00 15.00 100.00 15.00 100.00 15.00 100.00 15.00 Surfactant Solution C/NV T T T Pale Oil 40 (mL) 2.50 Y C X X X

TABLE 12 Variations of BSS51 with increasing the concentration of Emuldac ® 251PE BSS51 BSS62 BSS63 BSS64 wt % g wt % g wt % g wt % g Water (pH = 10.55) 38.00 5.70 37.00 5.55 36.00 5.40 35.00 5.25 Na₄EDTA (dry 6.00 0.90 6.00 0.90 6.00 0.90 6.00 0.90 granular) Butyl Carbitol 3.00 0.45 3.00 0.45 3.00 0.45 3.00 0.45 MEA 7.00 1.05 7.00 1.05 7.00 1.05 7.00 1.05 Tall Oil Fatty Acid 3.50 0.53 3.50 0.53 3.50 0.53 3.50 0.53 Dowfax ®C10L 11.00 1.65 11.00 1.65 11.00 1.65 11.00 1.65 Novel ®23E3 13.00 1.95 13.00 1.95 13.00 1.95 13.00 1.95 Tolytriazole CI 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 CIX-2 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 Emuldac 251PE 1.00 0.15 2.00 0.30 3.00 0.45 4.00 0.60 Grotan ® Biocide 1.00 0.15 1.00 0.15 1.00 0.15 1.00 0.15 Pale Oil 40 14.50 2.18 14.50 2.18 14.50 2.18 14.50 2.18 Total 100.00 15.00 100.00 15.00 100.00 15.00 100.00 15.00 Surfactant Solution C/NV T T T Pale Oil 40 (mL) 2.50 Y C X X X

TABLE 13 HFA-E composition BSS79 wt % g Water (pH = 10.55) 59.95 299.74 Na₄EDTA (dry granular) 2.36 11.78 Butyl Carbitol 5.30 26.51 Monethanol Amine 4.12 20.62 Tall Oil Fatty Acid 2.06 10.31 Dowfax ®C10L 5.30 26.51 Disulfonate Novel ®23E3 Ethoxylate 8.84 44.18 Tolytriazole CI 0.59 2.95 CIX-2 0.59 2.95 Emuldac ® 251PE 1.77 8.84 Grotan ® Biocide 0.59 2.95 Pale Oil 40 8.54 42.70 Total 100.01* 500.00 *Total is above 100% due to rounding off

Effect of Triethanolamine

A formulation was prepared by replacing MEA with TEA (triethanolamine) in a 1:1 molar equivalent (Table 14). The microemulsion was formed. Furthermore, formulations with mixtures of MEA and TEA were prepared and both their formulations and visual appearance are listed in Table 15.

TABLE 14 Formulation with replacing MEA with TEA as 1:1 molar equivalent in BSS57 BSS-81 wt % g Water (pH = 10.55) 53.97 53.97 Na4EDTA (dry 2.36 2.36 granular) Butyl Carbitol 5.30 5.30 Triethanolamine 10.10 10.10 Tall Oil Fatty Acid 2.06 2.06 Dowfax ®C10L 5.30 5.30 Disulfonate Novel ®23E3 Ethoxylate 8.84 8.84 Tolytriazole CI 0.59 0.59 CIX-2 0.59 0.59 Emuldac ® 251PE 1.77 1.77 Grotan ® Biocide 0.59 0.59 Pale Oil 40 8.54 8.54 Total 100.00 100.00 Surfactant Solution C/NV Pale Oil 40 (g) 8.54 Y C

TABLE 15 Formulations with mixtures of MEA and TEA BSS88 BSS89 BSS90 BSS91 wt % g wt % g wt % g wt % g Water (pH = 10.55) 58.95 11.79 57.95 11.59 56.95 11.39 55.95 11.19 Na₄EDTA (dry granular) 2.36 0.47 2.36 0.47 2.36 0.47 2.36 0.47 Butyl Carbitol 5.30 1.06 5.30 1.06 5.30 1.06 5.30 1.06 Monethanol Amine 4.12 0.82 4.12 0.82 4.12 0.82 4.12 0.82 Triethanolamine 1.00 0.20 2.00 0.40 3.00 0.60 4.00 0.80 Tall Oil Fatty Acid 2.06 0.41 2.06 0.41 2.06 0.41 2.06 0.41 Dowfax ®C10L Disulfonate 5.30 1.06 5.30 1.06 5.30 1.06 5.30 1.06 Novel ®23E3 Ethoxylate 8.84 1.77 8.84 1.77 8.84 1.77 8.84 1.77 Tolytriazole CI 0.59 0.12 0.59 0.12 0.59 0.12 0.59 0.12 CIX-2 0.59 0.12 0.59 0.12 0.59 0.12 0.59 0.12 Emuldac ® 251PE 1.77 0.35 1.77 0.35 1.77 0.35 1.77 0.35 Grotan ® Biocide 0.59 0.12 0.59 0.12 0.59 0.12 0.59 0.12 Pale Oil 40 8.54 1.71 8.54 1.71 8.54 1.71 8.54 1.71 Total 100.00 20.00 100.00 20.00 100.00 20.00 100.00 20.00 Surfactant Solution C/NV C/NV C/NV C/NV Pale Oil 40 (g) 1.71 Y C Y C Y C Y C

Effect of Choline Chloride

Other compositions were made with different concentrations of choline chloride to replace MEA in composition BSS57 (Table 16). The microemulsion was formed. Furthermore, formulations with mixtures of Choline Chloride with MEA or TEA were made and the results are reported in Table 17.

TABLE 16 Formulations with Choline Chloride BSS-82 BSS-83 BSS-84 BSS-85 wt % g wt % g wt % g wt % g Water (pH = 10.55) 54.65 54.65 63.57 63.57 63.18 63.18 62.57 62.57 Na₄EDTA (dry 2.36 2.36 2.36 2.36 2.36 2.36 2.36 2.36 granular) Butyl Carbitol 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 Choline Chloride 9.42 9.42 0.50 0.50 0.89 0.89 1.50 1.50 Tall Oil Fatty Acid 2.06 2.06 2.06 2.06 2.06 2.06 2.06 2.06 Dowfax ®C10L 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 Novel ®23E3 8.84 8.84 8.84 8.84 8.84 8.84 8.84 8.84 Tolytriazole CI 0.59 0.59 0.59 0.59 0.59 0.59 0.59 0.59 CIX-2 0.59 0.59 0.59 0.59 0.59 0.59 0.59 0.59 Emuldac ® 251PE 1.77 1.77 1.77 1.77 1.77 1.77 1.77 1.77 Grotan ® Biocide 0.59 0.59 0.59 0.59 0.59 0.59 0.59 0.59 Pale Oil 40 8.54 8.54 8.54 8.54 8.54 8.54 8.54 8.54 Total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 Surfactant Solution Phase separation C/NV C/NV C/NV Pale Oil 40 (g) 8.54 X Y C Y C Y C

TABLE 17 Formulations with Choline Chloride mixed with MEA or TEA BSS-86 BSS-87 wt % g wt % g Water (pH = 10.55) 60.00 60.00 60.00 60.00 Na4EDTA (dry granular) 2.36 2.36 2.36 2.36 Butyl Carbitol 5.30 5.30 5.30 5.30 Choline Chloride 0.89 0.89 0.89 0.89 Tall Oil Fatty Acid 2.06 2.06 2.06 2.06 Monoethanolamine 3.18 3.18 0.00 0.00 Triethanolamine 0.00 0.00 3.18 3.18 Dowfax ®C10L Disulfonate 5.30 5.30 5.30 5.30 Novel ®23E3 Ethoxylate 8.84 8.84 8.84 8.84 Tolytriazole CI 0.59 0.59 0.59 0.59 CIX-2 0.59 0.59 0.59 0.59 Emuldac ® 251PE 1.77 1.77 1.77 1.77 Grotan ® Biocide 0.59 0.59 0.59 0.59 Pale Oil 40 8.54 8.54 8.54 8.54 Total 100.00 100.00 100.00 100.00 Surfactant Solution C/NV C/NV Pale Oil 40 (g) 8.54 Y C Y C

Synthetic True Solution Formulations

Synthetic True Solutions are compositions which do not contain mineral oil. Instead, such compositions can contain polyalkylene glycol as a hydrodynamic lubricant. Semi-synthetic compositions developed in the previous section were used as the baseline for Synthetic True Solution Formulations with replacing Pale oil with UCON® 75-H-90,000 or UCON® 50-HB-100 and removing the two surfactants; Dowfax® C10L Disulfonate and Novel® 23E3 Ethoxylate.

UCON® 75-H-90,000 is a very viscous lubricant with a viscosity around 90,000 cP while UCON® 50-HB-100 is a low viscosity lubricant with a viscosity around 100 cP. The UCON® series of products is a water-soluble diol-initiated PAG in an aqueous solution.

Table 18 shows 4 formulations of similar composition while changing the content of UCON® 75-H-90,000. At room temperature, all formulations mixed very well into a clear solution. However, when these compositions were heated to 50° C. for a period of 10 minutes, compositions BTS1 and BTS2 immediately became turbid, while compositions BTS3 and BTS4 remained clear solutions. When cooled to RT, compositions BTS1 and BTS2 exhibited phase separation but when shaken, they reverted back to clear solutions.

TABLE 18 SynthetiC True Solution Formulations with UCON 75-H-90,000 BTS1 BTS2 BTS3 BTS4 wt % g wt % g wt % g wt % g Water 57 8.55 62 9.3 67 10.05 69.5 10.425 Na₄EDTA (dry 4 0.6 4 0.6 4 0.6 4 0.6 granular) Butyl Carbitol 9 1.35 9 1.35 9 1.35 9 1.35 Monoethanol amine 8 1.2 8 1.2 8 1.2 8 1.2 Tall oil fatty acid 4 0.6 4 0.6 4 0.6 4 0.6 CIX-2 1 0.15 1 0.15 1 0.15 1 0.15 Emuldac ® 251PE 1 0.15 1 0.15 1 0.15 1 0.15 Grotan ® Biocide 1 0.15 1 0.15 1 0.15 1 0.15 UCON 75-H-90,000 15 2.25 10 1.5 5 0.75 2.5 0.375 Total 100.00 15.00 100.00 15.00 100.00 15.00 100.00 15.00

Table 19 shows the formulation of the 4 compositions which were prepared. The compositions are similar with the only change residing in varying the concentration of UCON 50-HB-100®. At room temperature, all formulations mixed very well into a clear solution. However, when these formulations were heated to 50° C. for 10 minutes, BTS5 immediately became turbid, while compositions BTS6, BTS7, and BTS8 remained clear solutions. When cooled to RT, composition BTS5 showed phase separation, but when it was shaken, it reverted back to a clear solution.

TABLE 19 SynthetiC True Solution Formulations with UCON 50-HB-100 BTS5 BTS6 BTS7 BTS8 wt % g wt % g wt % g wt % g Water 57 8.55 62 9.3 67 10.05 69.5 10.425 Na₄EDTA (dry 4 0.6 4 0.6 4 0.6 4 0.6 granular) Butyl Carbitol 9 1.35 9 1.35 9 1.35 9 1.35 Monoethanol amine 8 1.2 8 1.2 8 1.2 8 1.2 Tall oil fatty aCid 4 0.6 4 0.6 4 0.6 4 0.6 CIX-2 1 0.15 1 0.15 1 0.15 1 0.15 Emuldac ® 251PE 1 0.15 1 0.15 1 0.15 1 0.15 Grotan ® Biocide 1 0.15 1 0.15 1 0.15 1 0.15 UCON 50-HB-100 15 2.25 10 1.5 5 0.75 2.5 0.375 Total 100.00 15.00 100.00 15.00 100.00 15.00 100.00 15.00

To understand whether the separation happened in the formulations with a high concentration of UCON®. A sample of 15 wt % UCON® 75-H-90,000 in water was prepared and then heated to 50° C. for 10 minutes and immediately it became turbid. It was determined that the cloud point of UCON® 75-H-90,000 depends on its concentration. When 2 wt % of Dowfax® C6L which is a good hydrotrope were added to the solution, it immediately became a clear solution as the heating continued. Nevertheless, this solution does not contain any additives that might affect the cloud point of UCON®.

To study the effect of Dowfax®C6L hydrotrope on the synthetic true solution formulations, a new set of formulations were prepared with 15 wt % UCON® 75-H-90,000 or UCON® 50-HB-100® and with variable concentration of Dowfax®C6L hydrotrope. All the samples prepared were clear solutions at RT. However, when heated to 50° C. for 10 minutes, all of them became turbid immediately.

TABLE 20 SynthetiC True Solution Formulations with UCON 75-H-90,000 and Dowfax C6L BTS9 BTS10 BTS11 BTS12 wt % g wt % g wt % g wt % g Water 56.5 8.48 56 8.4 55 8.25 53 7.95 Na₄EDTA (dry 4 0.6 4 0.6 4 0.6 4 0.6 granular) Butyl Carbitol 9 1.35 9 1.35 9 1.35 9 1.35 Monoethanol amine 8 1.2 8 1.2 8 1.2 8 1.2 Tall oil fatty aCid 4 0.6 4 0.6 4 0.6 4 0.6 Dowfax ®C6E 0.5 0.075 1 0.15 2 0.3 4 0.6 CIX-2 1 0.15 1 0.15 1 0.15 1 0.15 Emuldac 251PE 1 0.15 1 0.15 1 0.15 1 0.15 Grotan ® Biocide 1 0.15 1 0.15 1 0.15 1 0.15 UCON 75-H-90,000 15 2.25 15 2.25 15 2.25 15 2.25 Total 100.00 15.00 100.00 15.00 100.00 15.00 100.00 15.00

TABLE 21 Synthetic True Solution Formulations with UCON 50-HB-100 and Dowfax C6L BTS13 BTS14 BTS15 BTS16 wt % g wt % g wt % g wt % g Water 56.5 8.48 56 8.4 55 8.25 53 7.95 Na₄EDTA (dry 4 0.6 4 0.6 4 0.6 4 0.6 granular) Butyl Carbitol 9 1.35 9 1.35 9 1.35 9 1.35 Monoethanol amine 8 1.2 8 1.2 8 1.2 8 1.2 Tall oil fatty acid 4 0.6 4 0.6 4 0.6 4 0.6 Dowfax ®C6L 0.5 0.08 1 0.15 2 0.3 4 0.6 CIX-2 1 0.15 1 0.15 1 0.15 1 0.15 Emuldac 251PE 1 0.15 1 0.15 1 0.15 1 0.15 Grotan ® Biocide 1 0.15 1 0.15 1 0.15 1 0.15 UCON 50-HB-100 15 2.25 15 2.25 15 2.25 15 2.25 Total 100.00 15.00 100.00 15.00 100.00 15.00 100.00 15.00 Particle Size Distribution with DLS

The particle size distribution for HFA-E (composition set out in Table 13) was determined by dynamic light scattering (DLS) at 25° C. FIG. 1 shows the graphical representation of the results of the particle size distribution of the HFA-E composition. It is noteworthy to point out that the large part of the particles are much smaller than 10 nm in diameter.

Tribology Testing with MCR 302 Rheometer at 75° C.

Tribology testing was carried out on the following compositions: CaCl₂ (250 ppm dilution water); composition BTS40 (Synthetic #1 (MEA)); composition BTS41 (Synthetic #2 (MEA)); composition BTS42 (Synthetic #1 (TEA)); composition BTS43 (Synthetic #2 (TEA)); composition BSS79 (Semi-synthetic (MEA)); and composition BSS81 (Semi-synthetic (TEA)). FIG. 2 is a Stribeck curve for the above mentioned hydraulic fluid compositions.

All the developed compositions were determined to decrease the friction factor and prevent wear during the tests.

Thermal and Salinity Stability

Formulations were 2% active diluted in 250 ppm CaCl₂ solution. A set was observed at ambient temperature. The solutions remained clear for an extended period of time, no turbidity was developed due to the presence of the CaCl₂.

Another set was heated at 75° C. for 24 hr. Only composition BSS81 with TEA showed some haziness, very low turbidity. While for composition BSS79 with MEA, there was no significant change. For the synthetic compositions, there was no change in turbidity.

Corrosion Testing

Corrosion testing on aluminum, brass, chromium, and copper was conducted using diluted formulations to 0.8 wt % active. Tests were conducted at 75° C. for 24 hr. Formulations contain different combinations were tested (Table 22). The semi-synthetic composition was compatible with all metals and discoloration of weight loss/gain was recorded. Synthetic compositions show some discoloration with aluminum; however, no weight loss/gain was recorded. A photograph was taken of the coupons after the corrosion test for 24 hr at 75° C. with 0.8% active dilution in 300 ppm CaCl₂. Coupons of aluminum, brass, chrome, copper were tested and analyzed, they did not show any damage upon visual inspection.

TABLE 22 CI for each sample used in the corrosion tests Semi-Synthetic Formulations (Super Concentrate) BSS75 BSS76 BSS77 Tolytriazol 1.00 0.00 1.00 CIX-2 1.00 1.00 0.00 Active (%) 68.00 67.00 67.00

TABLE 23 CI for each sample used in the corrosion tests Synthetic Formulations (5% UCON 75-H-90,000) BTS34 BTS35 BTS36 Tolytriazol 1.00 0.00 1.00 CIX-2 1.00 1.00 0.00 Active (%) 37.00 36.00 36.00

TABLE 24 Corrosion Inhibitor for each sample used in the corrosion tests Synthetic Formulations (10% UCON 50-HB-100) BTS37 BTS38 BTS39 Tolytriazol 1.00 0.00 1.00 CIX-2 1.00 1.00 0.00 Active (%) 42.00 41.00 41.00

Additional formulations were developed and tested. These are listed in Table 25 below.

TABLE 25 Synthetic True Solution Formulations with UCON 50-HB-100 HFA-S N1 HFA-S N2 Ingredients wt % wt % Water, Distilled 74.5 68.997 Versene 100 5 11.00 Monethanol 8 8.000 amine Tall oil fatty acid 1 2.00 Tolytriazol 1.5 3.00 (granular) CIX-2 1 1.00 Emuldac 251PE 3 3.00 Grotan ® Biocide 1 1.00 UCON 50-HB- 5 2.00 100 KOH, 45% 0.0032 0.0032 Total 100 100

VERSENE® 100 Chelating Agent is an aqueous solution of the tetrasodium salt of ethylenediaminetetraacetic acid. Na₄EDTA is a very versatile, and widely used chelant for controlling metal ions over a broad pH range in aqueous systems.

UCON™ 50-HB-100 is a polyalkylene glycol (PAG) that is sold as a base stock for your formulation. UCON fluids and lubricants are synthetic, a key benefit to using our base stocks because they can be controlled and varied to achieve a level of performance not possible with natural oils and lubricants.

Corrosion Testing Procedure:

All testing for the hydraulic fluids were conducted at 2% v/v in 250 ppm CaCl₂ water. Six 24-hour corrosion test at room temperature were conducted using AL7075, CW505L, F12801, CDA110, chrome, and zinc coupons for each blend. Corrosion tests were executed in glass sample jars in a heated water bath. For each condition listed in Table 25, the coupon was washed with acetone, air dried, and weighed, before being suspended in the test fluid. The fluid in each glass sample jar was pre-heated up to temperature before exposing the coupon to the acid blend. After the exposure period, the coupon was removed, washed with water, followed by an acetone wash, air dried, and then weighed. The corrosion rate was determined from the weight loss, and the pitting index (Appendix A) was evaluated visually at 40× magnification, and a photo of the coupon surface at 40× magnification was taken. The results of this series of testing are reported in Table 26 below.

TABLE 26 Temperature 20° C. (68° C.) atmospheric pressure for a duration of 24 hours Coupon Corrosion Pitting Test Type Test Fluid mm/year lb/ft2 index A Al7075 Hydraclean HFA-S N1 0.138 0.000 3 B Brass Hydraclean HFA-S N1 0.005 0.000 0 C Cast Iron Hydraclean HFA-S N1 0.076 0.000 2 D Copper Hydraclean HFA-S N1 0.009 0.000 0 E Chrome Hydraclean HFA-S N1 0.000 0.000 0 F Zinc Hydraclean HFA-S N1 0.104 0.000 3 G Al7075 Hydraclean HFA-S N2 0.012 0.000 0 H Brass Hydraclean HFA-S N2 0.002 0.000 0 I Cast Iron Hydraclean HFA-S N2 0.045 0.000 2 J Copper Hydraclean HFA-S N2 0.000 0.000 0 K Chrome Hydraclean HFA-S N2 0.000 0.000 0 L Zinc Hydraclean HFA-S N2 0.058 0.000 2 Fins̆gar, M.; Jackson, J. Corrosion Science, 2014, 86, 17-41

Hard Water Stability Testing Procedure:

All testing for the hydraulic fluids were conducted at 2% v/v in 250 ppm CaCl₂ water. Hard water stability was performed by diluting the hydraulic fluid in a solution of 250 ppm CaCl₂ at 2% v/v loading and observing any changes. Photos of the diluted solutions were taken prior to the start of the testing. The diluted samples were then left at 20° C. for 72 hours (3 days). After the test period, photos of the two diluted solutions were taken to observe for any changes.

Results:

Photos of the diluted solutions prior to the start of the testing were taken in order to compare with aged solutions. Photos of the diluted solutions after 72 hours at 20° C. were taken. The photos were taken with a black background to observe the turbidity. No change, separation or increase in turbidity was observed for any of the blends.

Foamability and Foam Stability Testing Procedure:

All testing for the hydraulic fluids were conducted at 2% v/v in 250 ppm CaCl₂ water. Foam stability analysis was conducted on the KRUSS DFA100 Dynamic Foam Analyzer and compared using the ADVANCE software. Samples were prepared by measuring 50 mL of the test liquid into the foam analysis column. The flow rate was set to 0.3 L/min, foaming time was set to 20 s. Measurements were stopped after 20 minutes.

Results:

Results from the foam analysis test were obtained and upon analysis thereof, it was observed that the foam generation of the HFA-S N1 is slightly lower than that of HFA-S N2 and the foam stability decreases slightly faster in the HFA-S N1 than in the HFA-S N2.

Wear Testing Using Procedure:

Four ball wear test were conducted using 40 kg load at 12000 rpm speed and at 167° F. for 60 min following ASTM D4172. The wear was determined by measuring the scar size under a microscope. The results of this series of tests are reported in Table 27 below.

TABLE 27 Results of wear tests-Scar size for different HFA products Scar Product (mm) HFA-S N1 0.68 HFA-S N2 0.75 HFA-S NQ1 (Commercial Product) 0.68 HFA-S NQ2 (Commercial Product) 0.60

In general, a scar size less than 1 mm is acceptable. The formulations according to preferred embodiment of the present invention give results in the same range as the most commonly used commercial products.

Various requirements according to the technological criteria were investigated on the basis of the seventh Luxembourg Report about Requirements and Test for Fire Resistance Fluids used for Hydraulic Power Transmission and Controls were investigated for a composition according to a preferred embodiment of the present invention.

The HFA concentrate which was tested has the following characteristics:

-   -   Fluid density at 15° C.: 1.020 g/ml     -   Water content: 71.4%     -   Total acid number: 54.9 mg KOH/g     -   Kinematic viscosity at 20° C.: 5.02 mm²/s     -   Ash content: less than 0.01%     -   Flash point: higher than 100° C.

Compatibility of the fluid to various metals was assessed by corrosion testing at 35° C. for 28 days according to the Caterpillar longwall specification—EWN Part 1—3.3.1b, the results of the test are reported in Table 28 below:

TABLE 28 Corrosion testing results for a Fluid according to the present invention according to the Caterpillar longwall specification-EWN Part 1-3.3.1b The effects on each metal test piece and the fluids-to be noted according to the classification at the Luxembourg report Test piece Visual Visual Increase or fluid effects in effects in decrease mg Visual effects the fluid the test phase test piece Steel 0 0 0 −2 Copper 0 0 0 <+1 Zinc 0 0 1 +3 Aluminium 0 0 0 <+1 Brass 0 0 0 <+1 Copper/zinc 0 0 0/1 <+1/+5 aluminum/zinc 0 0/0 0/1 <+1+3 steel/aluminium 0 0/1 0/0 −7/+4 steel/zinc 0 0/1 0/1 −8/+2 Fluid without test 0 — — — piece

Determination of Foam Characteristics

The foaming characteristics of a fluid according to a preferred embodiment of the present invention was assessed by according to the Caterpillar longwall specification—EWN Part 1—3.3.1b, EU-SFP 02791 2vol % in Y-water. The results are reported in Table 29 below.

TABLE 29 Results of the testing to determine foam Characteristics of a preferred embodiment of the present invention in accordance with the Caterpillar longwall specification-EWN Part 1-3.3.1b, EU-SFP 02791 2vol % in Y-water Volume of foam Volume of foam Temp. of Fluid measured after the air measured after a settling sample flow is stopped time of 10 minutes ° C. (ml) (ml) 25 150 10 50  60 10 25 after 50 260 10

Assessment: the volume of foam measured by the above method test should not exceed the following values: immediately after the air flow is stopped: 300 ml; and immediately after 10 minutes settling period: 10 ml. The fluid sample tested met the requirements of this test.

Testing to Determine Compatibility with Hydrocor CV 50 DF

A number of tests were carried out to determine the compatibility the fluid according to a preferred embodiment of the present invention with Hydrocor CV 50 DF and EU-SFP 02791 2vol % in y-water 20:80, as well as Hydrocor CV 50 DF and EU-SFP 02791 2vol % in y-water 50:50, as well as Hydrocor CV 50 DF and EU-SFP 02791 2vol % in y-water 80:20. Each test confirmed that the fluid was compatible in each circumstance.

Additional Corrosion Testing

The fluid according to a preferred embodiment of the present invention was tested for corrosion (crevice corrosion test as per DSK N 762 830) on a unit where the volume q was 2 vol. % for a duration of 21 days at a temperature of 35° C. and a relative air humidity of 95%.

The testing involved visual analysis of the deposits prior to cleaning, tarnishing after cleaning and solid deposits on the interior of the tube around the split of the outer pipe and on the surface of the bronze plunger. Only some deposits were noted around the split, otherwise not tarnishing was noted and no deposits on the interior of the pipe were noted. No corrosion damage was noted on any of the parts.

Additional testing including bacteria resistance and compatibility with various elastomeric materials at 60° C., Thermal Stability (at 70° C. for 168 hours), standard elastomer swell test, side valve flap test and Joy mining solenoid testing indicated that the composition according to a preferred embodiment of the present invention passed the requirements set out by each one of those tests as well.

While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be appreciated by those skilled in the relevant arts, once they have been made familiar with this disclosure that various changes in form and detail can be made without departing from the true scope of the invention in the appended claims. 

1. A semi-synthetic fire-resistant hydraulic fluid composition comprising: water in an amount ranging from 25-65 wt %; a hydrophilic co-solvent present in an amount ranging from 5 to 20 wt %; an oil component present in an amount ranging from 1-30 wt %; a lubricant present in an amount ranging from 1 to 10 wt %; optionally, a vapor corrosion inhibitor (VCI) present in an amount ranging from 1 to 10 wt %; a neutralizing agent (which neutralizes the tall oil fatty acid) present in an amount ranging from 1 to 10 wt %; a nonionic surfactant present in an amount ranging from 5 to 25 wt %; an anionic surfactant present in an amount ranging from 5 to 25 wt %; optionally, a corrosion inhibitor present in an amount ranging from 0.5 wt % to 5 wt %; optionally, an anti-foaming agent present in an amount ranging from 0.5 wt % to 5 wt %; and optionally, a biocide present in an amount ranging from 0.5 wt % to 5 wt %.
 2. The composition according to claim 1, further comprising a chelating agent present in an amount ranging from 2 to 10 wt %.
 3. The composition according to claim 1, where said oil component is pale oil.
 4. The composition according to claim 1, where said oil component is present in an amount ranging from 5 wt % to 20 wt %.
 5. The composition according to claim 1, where said lubricant is a tall oil fatty acid.
 6. The composition according to claim 1, where said lubricant is present in an amount ranging from 2-5 wt %.
 7. The composition according to claim 1, where said neutralizing agent is selected from the group consisting of: primary amine, tertiary amines.
 8. The composition according to claim 1, where said nonionic surfactant is a linear alcohol ethoxylate with C9 to C15, ethylene oxide 1 to
 10. 9. The composition according to claim 1, where said anionic surfactant is selected from the group consisting of: sulfonate surfactant; disulfonate surfactant; and DDBSA and combinations thereof.
 10. The composition according to claim 1, wherein the nonionic surfactant and the anionic surfactant are present in a weight ratio ranging from 1:3 to 3:1.
 11. The composition according to claim 1, where the VCI and the neutralizing agent are the same compound.
 12. The composition according to claim 1, where the VCI is selected from the group consisting of: monoethanolamine; triethanolamine; and the like.
 13. The composition according to claim 1, said composition comprising an emulsion having a particle diameter size of less than 10 nm (MEA).
 14. The composition according to claim 1, said composition comprising an emulsion having a particle diameter size of less than 150 nm (TEA).
 15. The composition according to claim 1 where the anionic surfactant is selected from the group consisting of: Dowfax 10CL.
 16. Composition according to claim 1 where the nonionic surfactant is selected from the group consisting of: Novel® 23E3.
 17. Composition according to claim 1 where the neutralizing agent is chlorine chloride.
 18. Composition according to claim 1 where the hydrophilic co-solvent is butyl cartbitol.
 19. A synthetic fire-resistant hydraulic fluid comprising: water in an amount ranging from 25-65 wt %; a hydrophilic co-solvent present in an amount ranging from 5 to 20 wt %; a polyalkylene glycol compound present in an amount ranging from 1 to 30 wt %; a lubricant present in an amount ranging from 1 to 10 wt %; optionally, a vapor corrosion inhibitor (VCI) present in an amount ranging from 1 to 10 wt %; a neutralizing agent present in an amount ranging from 1 to 10 wt %; optionally, a corrosion inhibitor present in an amount ranging from 0.5 wt % to 5 wt %; optionally, an anti-foaming agent present in an amount ranging from 0.5 wt % to 5 wt %; and optionally, a biocide present in an amount ranging from 0.5 wt % to 5 wt %.
 20. The composition according to claim 19, further comprising a chelating agent present in an amount ranging from 2 to 10 wt %.
 21. The composition according to claim 19, where the polyalkylene glycol compound is selected for the group consisting of: UCON® 75-H-90,000 and while UCON® 50-HB-100.
 22. The composition according to claim 19, where said oil component is present in an amount ranging from 5 wt % to 20 wt %.
 23. The composition according to claim 19, where said lubricant is a tall oil fatty acid.
 24. The composition according to claim 19, where said neutralizing agent is selected from the group consisting of: primary amine, tertiary amines.
 25. The composition according to claim 19, where the VCI is selected from the group consisting of: monoethanolamine; triethanolamine; and the like. 